Is it possible to write-protect the hard disk with software only?

The answer is no. There are several programs that claim to do this, but *all* of them can be bypassed with techniques already used by some viruses. Therefore you should never rely on such programs *alone*, although they can be useful in combination with other antivirus measures.

1st Security Agent

Mail Bomber

Security Administrator

PC Lockup

Access Lock

Access Administrator Pro

ABC Security Protector

1st Security Agent

Mail Bomber

Security Administrator for Windows

PC Lockup

Access Lock

Access Administrator

ABC Security Protector

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